I made yogurt yesterday and it was fantastic! I made it like 10 years ago and it sucked bad.
I microwaved fat free milk, 2 qts for 17 min, it was about 180 degrees. Set it in a sink that was 1/2 way up the bowl with cold water and let it sit 10 minutes till it got to 110 degrees.
Mixed in 4 TB (about) regular yogurt (I used vanilla and made sure it didn't expire for a long time) for the probiotics. I also added a few TB of honey because I was afraid it would be bitter.
Let sit covered (I used a plate) and wrapped in a towel in your oven with just the light on for 8 hours.
You can strain it with cheesecloth at this point if you want greek yogurt, you pour into the cheesecloth gently and let sit a few more hours to strain out the clear stuff.
Store in the fridge and you can use this next time as your started instead of buying yogurt. According to the youtube video I watched (salad in a jar lady) you can use any form of milk including non dairy or any amount of fat to make yogurt. Might try half almond milk next time!